Summarizing all of the above:
There are two simle ways doing this:
Through the webbrowser
One the command line
Depending on you installation you might've installed PHP as a command line tool (I'm running 4.3.0, and it works fine). The file you'll need to look for is called [FONT=courier new]php[/FONT], and is typically found under [FONT=courier new]/usr/local/bin[/FONT]. There are loads of tutorials on how to create command-line (CLI) PHP-scripts, so I'm not going to explain that here..
If you're php-installation doesn't support CLI-scripts, you might be able to solve this problem this way instead:
Create a dir under your webroot (ie [FONT=courier new]/usr/local/www/www.your_host.com/this_is_the_new_dir[/FONT]).
Create your script as a standard PHP-script and store in the newly created dir.
Make sure the dir is password-protected (how this is done depends on your http daemon).
Create a cron job that executes lynx like this:
[FONT=courier new]lynx -dump [url]http://username:password@www.your_host.com[/url][/FONT]
This ought to do it.. 🙂
Good luck!
Olle